A beacon light such as, for example, an aircraft obstruction light, can be used to mark an obstacle that may provide a hazard to aircraft navigation. Beacon lights are typically used on buildings, towers, and other structures taller than about 150 feet. Previous beacon lights were made using traditional light sources such as incandescent or high intensity discharge lamps. These traditional light sources emit infrared (IR) light as well as visible light making them visible to pilots with aviator night vision imaging systems (ANVIS).
However, some recent beacon lights use light sources that provide little or no light in the IR part of the electromagnetic spectrum. As a result, these types of light sources are not visible to pilots with ANVIS.